Slit valve door with moving mating part

ABSTRACT

Embodiments disclosed herein generally relate to a slit valve door assembly for sealing an opening in a chamber. A slit valve door that is pressed against the chamber to seal the slit valve opening moves with the chamber as the slit valve opening shrinks so that an o-ring pressed between the slit valve door and the chamber may move with the slit valve door and the chamber. Thus, less rubbing of the o-ring against the chamber may occur. With less rubbing, fewer particles may be generated and the o-ring lifetime may be extended. With a longer lifetime for the o-ring, substrate throughput may be increased.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.12/548,553 (APPM/13375), filed Aug. 27, 2009, which application claimsbenefit of U.S. Provisional Patent Application Ser. No. 61/092,480(APPM/13375L), filed Aug. 28, 2008, both of which are hereinincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments disclosed herein generally relate to a slit valve door forsealing an opening in a chamber.

2. Description of the Related Art

In order to introduce a substrate to a chamber, a door is typicallyopened and the substrate is inserted thorough an opening into theinterior volume of the chamber. The door is then closed and a vacuum isdrawn. As the vacuum is drawn, the chamber may compress in on itself andhence, the opening may shrink due to the chamber movement. When thechamber is vented, the chamber may return to its normal state.

The door, when sealed to the chamber, may remain stationary because itis not a part of the chamber wall. The sealing mechanism, typically ano-ring, is compressed between the door and the chamber wall. Thus, thechamber, as it compresses or vents, moves relative to the door ando-ring and rubs against the o-ring and potentially the door. Because thechamber rubs against the o-ring, the o-ring may break and the seal maybe broken to compromise the vacuum integrity of the chamber.Additionally, particles may be generated due to the rubbing.

Therefore, there is a need in the art for a chamber and door arrangementthat prevents the generation of particles while maintaining vacuumintegrity.

SUMMARY OF THE INVENTION

Embodiments disclosed herein generally relate to a slit valve doorassembly for sealing an opening in a chamber. A slit valve door that ispressed against the chamber to seal the slit valve opening moves withthe chamber as the slit valve opening shrinks so that an o-ring pressedbetween the slit valve door and the chamber may move with the slit valvedoor and the chamber. Thus, less rubbing of the o-ring against thechamber may occur. With less rubbing, fewer particles may be generatedand the o-ring lifetime may be extended. With a longer lifetime for theo-ring, substrate throughput may be increased.

In one embodiment, a slit valve door includes a door body having a firstbody, a second body, and a third body. The second body and third bodyeach may be coupled to the first body at an edge thereof and spacedapart from the first body in a center area thereof. The slit valve doormay also include one or more bellows coupled between the first body andat least one of the second body and the third body so that the distancebetween a seal on the second body and a seal on the third body can varywith any variation in the width of the slit valve door.

In another embodiment, a slit valve door includes a first body, a secondbody spaced from the first body and a first bellows coupled between thesecond body and first surface of the first body. The slit valve door mayalso include a second bellows coupled between the second body andsecond, third, fourth, and fifth surfaces of the first body such that anair pocket is present between the first body, the second body, the firstbellows, and the second bellows.

In another embodiment, a load lock chamber includes a load lock chamberbody. At least one opening may be formed through a surface of the loadlock chamber body. The load lock chamber may also include a slit valvedoor. The slit valve door may include a door body having a first body, asecond body, and a third body. The second body and the third body eachmay be coupled to the first body at an edge thereof and spaced apartfrom the first body in a center area thereof. The slit valve door mayalso include one or more bellows coupled between the first body and atleast one of the second body and the third body, and a slit valve dooractuator coupled with the slit valve door and the chamber body.

In another embodiment, a load lock chamber includes a load lock chamberbody having at least one opening formed through a surface of the loadlock chamber body. The load lock chamber also includes a slit valvedoor. The slit valve door includes a first body having a second surface,third surface, fourth surface, fifth surface, sixth surface, and seventhsurface. The slit valve door also includes a second body spaced from thefirst body and a first bellows coupled between the second body and theseventh surface. The slit valve door also includes a second bellowscoupled between the second body and second, third, fourth, and fifthsurfaces of the load lock chamber body such that an air pocket ispresent between the first body, the second body, the first bellows, andthe second bellows. The load lock chamber may also include a slit valvedoor actuator coupled with the slit valve door and the chamber body.

In another embodiment, a slit valve door is disclosed. The slit valvedoor includes a first body and a second body coupled to the first bodyat an edge thereof and spaced from the first body such that a first slitis present between the first body and the second body. The slit valvedoor also includes a first bearing plate coupled between the first bodyand the second body, a first bellows coupled between the first body andthe second body and over the first slit and a first clamp coupled to thefirst bellows, the first body and the second body.

In another embodiment, a method of evacuating a chamber is disclosed.The method includes compressing an o-ring between a slit valve door anda chamber body, the slit valve door having a first portion and a secondportion, drawing a vacuum within the chamber body and moving the chamberbody, the o-ring and the first portion relative to the second portion.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A is a schematic front view of a chamber 100 prior to evacuationwith a slit valve door removed.

FIG. 1B is a schematic front view of the chamber 100 of FIG. 1A undervacuum with the slit valve door removed.

FIGS. 2A-2F are schematic cross sectional views of slit valve doors thatmay be used to deflect with the chamber body when the chamber bodydeflects under vacuum.

FIGS. 3A and 3B are isometric views of a slit valve door according toone embodiment.

FIG. 3C is a schematic cross sectional view of a slit valve door 350.

FIG. 4A is a front view of a slit valve door prior to evacuating achamber.

FIG. 4B is a front view or another slit valve door prior to evacuatingthe chamber.

FIG. 4C is a cross sectional view of an apparatus having two separatevolumes prior to evacuating one of the volumes.

FIG. 4D is a front view of a slit valve door that has been coupled to anevacuated chamber.

FIG. 4E is a front view of a slit valve door that has been coupled to achamber adjacent to an evacuated chamber.

FIG. 4F is a schematic cross sectional view of a chamber showing anevacuated chamber volume adjacent an atmospheric chamber volume.

FIGS. 5A-5C are cross sectional views of a slit valve door according toone embodiment.

FIGS. 5D and 5E are isometric views of a slit valve door according toanother embodiment.

FIGS. 5F-5J are isometric views of a slit valve door according toanother embodiment.

FIG. 6A is an isometric view of a slit valve door according to anotherembodiment.

FIG. 6B is a blown up view of the slit valve door of FIG. 6A.

FIG. 7 is a schematic top view of a cluster tool according to oneembodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

Embodiments disclosed herein generally relate to a slit valve doorassembly for sealing an opening in a chamber. A slit valve door that ispressed against the chamber to seal the slit valve opening moves withthe chamber as the slit valve opening shrinks so that an o-ring pressedbetween the slit valve door and the chamber may move with the slit valvedoor and the chamber. Thus, less rubbing of the o-ring against thechamber may occur. With less rubbing, fewer particles may be generatedand the o-ring lifetime may be extended. With a longer lifetime for theo-ring, substrate throughput may be increased.

One of the major problems in load lock doors is the relative movement ofthe sealing surface of the load lock in relation to the door. The matingsurface is the load lock chamber that goes through vacuum cycling thatleads to a considerable movement. Because the door is fairly rigid anduncompromising, and because the o-ring is subjected to a significantabrasion/erosion mechanism, a lot of particles can be generated thatleads to the seal to be compromised in a short period of time. Theembodiments discussed herein provide for the flexibility of the o-ringgroove area of the door that mates with the moving part so that therelative movement is minimized. The flexibility is achieved by providingtwo long slots through the length of the door and then covering the slotwith a flexible sealing gasket (such as a diaphragm) to maintain vacuumintegrity. In order to maintain the door's mechanical integrity, theflexible area may be coupled to the rigid part of the door through aseries of pins and bushings that allows vertical movement and limitslateral movement.

The embodiments described herein will be described below in regards to atriple slot load lock chamber available from AKT America, Inc., asubsidiary of Applied Materials, Inc., Santa Clara, Calif. While theembodiments will be described below in regards to a load lock chamber,it is to be understood that the embodiments may be practiced in othervacuum chambers including those produced by other manufacturers.

FIG. 1A is a schematic front view of a chamber 100 prior to evacuationwith a slit valve door removed. The chamber 100 may be a load lockchamber, a processing chamber or any general chamber that may beevacuated. The chamber 100 includes a chamber body 102 having a slitvalve opening 104 through one or more walls of the chamber body 102. Theslit valve opening 104 has a height shown by arrows “A”. However, whenthe chamber 100 is evacuated, the slit valve opening 104 may shrink.

FIG. 1B is a schematic front view of the chamber 100 of FIG. 1A undervacuum with the slit valve door removed. As shown, the slit valveopening 104 has pinched in the middle because the chamber body 102 hasmoved from the normal position shown by lines 106, 108, 112, 110 adistance shown by arrows “B”. The chamber body 102 pinches in more inthe center of the slit valve opening 104 because there is no support inthe center area of the slit valve opening 104 when the chamber body 102deflects under vacuum. For large area chambers, such as chamber sized toprocess substrates having an area of greater than about 1 square meter,the deflection may be quite pronounced. Because the chamber moves, theslit valve door (not shown), may rub against the chamber body 102 andgenerate particles if the slit valve door does not move.

FIGS. 2A-2F are schematic cross sectional views of slit valve doors thatmay be used to deflect with the chamber body when the chamber bodydeflects under vacuum. In the embodiment shown in FIG. 2A, the slitvalve door 200 may be actuated by rotating the rotating handle 208 aboutits axis of rotation. The rotating handle 208 may be coupled with thecentral body 202 of the slit valve door 200 by a coupling handle 210.

The slit valve door 200 comprises a first body 202, a second body 204,and a third body 206. In one embodiment, the first body 202 and thesecond and third bodies 204, 206 comprise separate pieces coupledtogether at the ends thereof and spaced apart at a center area thereof.In another embodiment, the first body 202 and the second and thirdbodies 204, 206 comprise a unitary piece of material spaced apart at acenter area thereof. A rod 214 may be coupled between each of the secondand third bodies 204, 206 and the first body 202. A cap portion 218 maybe present on the second and third bodies 204, 206 over the rod 214 ifdesired. The rod 214 may be fixedly coupled to the first body 202, butslidably coupled to the second and third bodies 204, 206 such that therod 214 remains stationary relative to the second and third bodies 204,206 when the second and third bodies 204, 206 move relative to the firstbody 202. The second and third bodies 204, 206, may slide and moverelative to the first body 202 such that the second and third bodies204, 206 move closer to the first body 202 when a vacuum is drawn in thechamber. The second and third bodies 204, 206 may slide because theO-ring 220 that is coupled thereto is pressed against the chamber wallto seal the chamber. When the chamber moves or deflects relative to itsnormal position, so will the O-ring 220 and hence, the second and thirdbodies 204, 206 that are coupled to the chamber wall. Thus, while therod 214 remains stationary, the second and third bodies 204, 206 slideand move relative to the first body 202 and closer or further away fromthe first body 202. FIG. 2A shows the slit valve door 200 where thesecond and third bodies 204, 206 have been compressed closer to thefirst body 202. FIG. 2D shows the slit valve door 200 where the secondand third bodies 204, 206 are not compressed closer to the third body202. A bushing 216 may be present between the second and third bodies204, 206 and the rod 214 to permit the second and third bodies 204, 206to move with as little friction as possible. In one embodiment, thebushing 216 may comprise polytetrafluoro ethylene. The rods 214 may bespaced along the slit valve door 200. In one embodiment, the first body202, the second and third bodies 204, 206, the rod 214, and the cap 218each comprise a metal material. In another embodiment, the first body202, the second and third bodies 204, 206, the rod 214, and the cap 218comprise aluminum.

To ensure that the slit valve door 200 is able to seal the processingchamber, bellows 212 may be present on the side of the slit valve door200 that will face the vacuum environment. The bellows 212 may compressas the second and third bodies 204, 206 move closer to the first body202. Similarly, the bellows 212 may expand as the second and thirdbodies 204, 206 move farther away from the first body 202. The bellows212 may be a vacuum bellows capable of maintaining a vacuum such thatthe vacuum environment is not compromised by the bellows 212. Thebellows 212 on the vacuum side isolate the rods 214 and the bushing 216from the vacuum environment and thus, any particles generated by thebushing 216 and rods 214 rubbing may be prevented from reaching thevacuum environment and potentially contaminating the substrates.

During operation, the slit valve door 200 is rotated into place relativeto the chamber whereby the O-ring 220 is brought into contact with thevacuum chamber. The vacuum is then drawn in the vacuum chamber. As thevacuum is drawn, the O-ring 220 and hence, the second and third bodies204, 206 move with the vacuum chamber body relative to the first body.In so moving, the second and third bodies 204, 206 may move relative tothe first body 202 and the rod 214. Additionally, the bellows 212compress. Thus, the second and third bodies 204, 206, the bushing 216,and the cap portion 218 all move relative to the first body 202. Whenthe vacuum chamber is vented, the second and third bodies 204, 206 againmove relative to the first body 202 and the rod 214. However, duringventing, the second and third bodies 204, 206, the bushing 216, and thecap portion 218 all move away from the first body 202 and the rod 214.Additionally, the bellows 212 expands. Thereafter, the slit valve door200 may be moved away from the vacuum chamber. In the embodiment shownin FIG. 2B, a bellows 232, 234 is present on both the vacuum side andthe other side of the slit valve door 230. FIG. 2B shows the slit valvedoor 230 where the second and third bodies have been compressed closerto the first body. FIG. 2E shows the slit valve door 230 where the endpieces are not compressed closer to the first body.

In FIG. 2C, the slit valve door 250, the first body 252 is spaced fromthe second and third bodies 254, 256 by an air gap 264 that is bound bya bellows 258, 260 on both sides of the slit valve door 250. The airthat is present in the air gap 264 vents out of the air gap 264 througha filter 262 when the second and third bodies 254, 256 compress towardsthe first piece 252. Similarly the filter 262 permits air to enter theair gap 264 when the second and third bodies 254, 256 expand away fromthe first piece 252. FIG. 2C shows the slit valve door 250 where thesecond and third bodies 254, 256 have been compressed closer to thefirst body 252. FIG. 2F shows the slit valve door 250 where the secondand third bodies 254, 256 are not compressed closer to the first body252.

FIGS. 3A-3B are isometric views of a slit valve door 300 according toone embodiment. The slit valve door 300 is coupled to a shaft 302 and asupport/mount 304. The shaft 302 rotates about its axis of rotation topivot the slit valve door 300. The coupling handle is coupled to theshaft 302 and the first body 306 of the slit valve. Thus, when thesecond and third bodies 308, 310 compress towards and expand away fromthe first body 306, the support/mount 304 remains stationary with thecenter body 306. The second and third bodies 308, 310 are coupled to thefirst body 306 at the edges 312, 314 such that the first body 306 andthe second and third bodies 308, 310 comprise a single, unitary piece ofmaterial. In one embodiment the single, unitary piece of materialcomprises aluminum. The second and third bodies 308, 310 may be spacedfrom the first body 306 by spaces 316, 318 in the areas of the secondand third bodies 308, 310 that may compress and/or expand relative tothe first body 306 during evacuation and venting. There are several rod318 locations along the slit valve door 300.

FIG. 3C is a schematic cross sectional view of a slit valve door 350having top and bottom slots 352 to permit portions of the slit valvedoor 350 to move with the chamber body when the chamber body deflects. Abellows 354 may be placed over the slots 352 and held in place by aclamp 356. The clamp 356 and bellows 354 may either face into or awayfrom the interior of the chamber.

FIG. 4A is a front view of a slit valve door 400 prior to evacuating achamber. FIG. 4B is a front view of a slit valve door 416 prior toevacuating a chamber. FIG. 4C is a cross sectional view of a load lockchamber 404 having two separate, environmentally isolated volumes 420,422 prior to evacuating the load lock apparatus 404. FIG. 4D is a frontview of the slit valve door 400 that has been coupled to an evacuatedchamber volume 420. FIG. 4E is a front view of the slit valve door 416that has been coupled to a chamber volume 422 adjacent the evacuatedchamber volume 420. FIG. 4F is a cross sectional view of the apparatus404 after evacuating volume 420. As shown in FIG. 4A, the gaps 402between the center piece and the end pieces (i.e., the pieces spacedfrom the center piece) are shown by arrow “E”. The gaps 402 create asubstantially uniform distance between the end pieces and the centerpiece for the entire gap 402. Prior to evacuation, the bellows 414 forthe door 400 are in an intermediate position. Similarly, the bellows 418for the doors 416 that seal volume 422 are also at an intermediateposition.

The slit valve door 416 shown in FIG. 4B is similar to the slit valvedoor 400 shown in FIG. 4A. The gaps 424, 426 between the end pieces andthe center piece are shown by arrow “I”. The gaps 424, 426 create asubstantially uniform distance between the end pieces and the centerpiece for the entirety of the gaps 424, 426.

When the slit valve door 400 is coupled to the apparatus 404 and thevolume 420 evacuated, the walls 406, 408 of the load lock chamber 404compress in from their normal positions shown by lines “G”, “H”, andcause the gap 402 of the slit valve door 400 to compress as shown byarrow “F” such that the distance between the end pieces and the centerpiece gradually decreases from the edge 410 of the gap 402 to the center412 of the gap 402. The bellows 414 of the door 400 compress as shown inFIG. 4F. Because the wall 408 deflects toward the evacuated volume 420,the door 416 expands the thus expands the bellows 418 to a stretchedstate shown in FIG. 4E.

For the atmospheric volume 422, the slit valve door 416 expands and thusstretches the bellows 418 for the top gap 424 as shown by arrows “J”while the bottom gap 426 remains relatively unchanged as shown by arrows“K”. However, the gap 426 may stretch as much as gap 424. In oneembodiment, the gap 426 may stretch less than gap 424. In oneembodiment, the gap 426 remains unchanged such that the gap 426 isseparated by a distance represented by arrows “K” that substantiallyequals the distance represented by arrows “I”. Gap 424 expands becauseit is directly adjacent to the deflected chamber wall while the gap 426is directly adjacent to a wall that may not deflect. The expansion orcompression of the gaps 402, 424, 426 means that the end pieces aremoving relative to the central piece. Similarly, O-rings 428, 430, 432,434 move relative to the central piece. The O-rings 428, 430, 432, 434are shaped substantially identical to the gaps 402, 424, 426, but areslightly larger. Thus, the O-rings 428, 430, 432, 434 shape mimics theshape of the gaps 402, 424, 426. The area of the gaps 402, 424, 426where the most movement occurs will also be the area of the O-rings 428,430, 432, 434 that have the most movement relative to the central piece.The O-rings 428, 430, 432, 434 move with the deflecting chamber wallsand the moving portions of the slit valve doors 400, 416 such that theO-rings 428, 430, 432, 434 do not move relative to the deflectingchamber walls or the portions of the slit valve doors 400, 416 thatmove. Hence, the locations of the gaps 402, 424, 426 where the leastamount of movement or no movement occurs will experience the leastamount of movement or no movement for the O-rings 428, 430, 432, 434.Put another way, the long side of the O-rings 428, 430, 432, 434 willmove while the short side of the O-rings 428, 430, 432, 434 will movelittle or not at all.

FIGS. 5A-5C are cross sectional views of a slit valve door 500 accordingto one embodiment. The slit valve door 500 may comprise a first body 502and a second body 504. An O-ring 506 may be coupled with the second body504 to permit the slit valve door 500 to seal to a chamber. The secondbody 504 may comprise a separate piece from the first body 502 that ismovable relative to the first body 502. When pressed against a chamber,the second body 504 may move with the chamber and relative to the firstbody 502. Thus, the O-ring 506 may remain stationary relative to thechamber (but move relative to the first body) and no parts of the slitvalve door 500 and the chamber rub against each other. Due to themovement of the second body 504 with the chamber, the amount ofparticles generated that may contaminate the substrate may be reduced.

The second body 504 may slide along a bearing 514 positioned between thesecond body 504 and the first body 502. In one embodiment, the bearing514 may comprise poly ether ether ketone. In another embodiment, thebearing 514 may comprise polytetrafluoro ethylene.

The moving second body 504, because it moves relative to the first body502, may produce particles that could contaminate a substrate. Thus, thelocations of the slit valve door 500 where any particles may begenerated due to moving parts may be sealed from exposure to thesubstrates and the vacuum environment. One such area where particles maybe generated is the interface between the second body 504 and thebearing 514. The particles formed may fall into the cavity 518 betweenthe second body 504 and the first body 502. Thus, a bellows 510 may befastened to the second body 504 as well as the first body 502 to isolatethe cavity 518 from the sealing side of the slit valve door 500. Thebellows 510 may be coupled to the second body 504 and the first body 502by one or more fastening mechanisms 516.

To provide additional coupling of the second body 504 to the first body502, a second bellows 508 may be coupled between the second body 504 andthe first body 502 along the top of the slit valve door 500. One or morefastening mechanisms 512 may be used to couple the bellows 508 to thefirst body 502 and the second body 504.

The cavity 518 may be maintained at approximately the same pressure asthe pressure side of the slit valve door 500. In one embodiment, thepressure of the pressure side of the slit valve door 500 may beatmospheric pressure. By maintaining the cavity 518 at approximately thesame pressure as the pressure side of the slit valve door 500, thesecond body 504 may maintain its position relative to the first body 502even when the chamber to which the slit valve door 500 is sealed isvented or evacuated. The predominate force on the second body 504 may befrom the O-ring 506 contact with its sealing surface on the chamber. Toachieve the equal pressure condition, the top bellows 508 may comprise afine porosity material. In one embodiment, the porosity may be about 1micrometer. The porosity may permit the cavity 518 to breathe whilecontaining any particles generated by the moving parts. In oneembodiment, the top bellows 508 may comprise solid elastomer, butbreathable filter plugs may connect into the cavity 518 from thepressure side.

FIG. 5B shows the fastening mechanism 520 that couples the second body504 to the first body 502 through the bearing 514. The fasteningmechanism 520 may be disposed in a slot 522 formed in the second body504. When the chamber is evacuated and the corner piece moves, thefastening mechanism 520 remains stationary relative to the second body504 and the slot 522 moves relative to the fastening mechanism 520. FIG.5C shows the second body 504 in a displaced condition. As shown, theslot 522 is moved relative to the fastening mechanism 520.

FIGS. 5D and 5E are isometric views of a slit valve door 530 accordingto one embodiment. FIG. 5D shows the non-sealing side of the slit valvedoor 530 with where the shaft 532 and support/mount 534 are located. Theslit valve door 530 may rotate about the shaft 532 to position the slitvalve door 530 against and away from the chamber. The support/mount 534couples the shaft 532 to the first body 536.

FIG. 5E shows the sealing side of the slit valve door 530. As shown, thesecond body 538 may span a considerable length of a side of the firstbody 536. It is to be understood that the second body 538 could span theentire side of the first body 536. Additionally, the second body 538could span the areas where the slit valve door 530 is expected to movewhen the chamber moves. As can be seen from FIG. 5E, the O-ring 540traverses both the second bodies 538 and the first body 536. In thesituation where the second body 538 spans less than the entire length ofa side of the first body 536, additional bellows may be necessary at thevertical interfaces of the second bodies 538 and first body 536respectively. In one embodiment, the bellows for the vertical interfacesare unitary with the bellows.

FIGS. 5F-5J are isometric views of a slit valve door 550 according toanother embodiment. The slit valve door 550 may rotate or pivot about arod 552 to compress an O-ring 554 against a sealing surface. The slitvalve door 550 includes a door body 576 having two substantiallyparallel slits 578 formed therein to permit movement of portions of theslit valve door 550 when the chamber to which the slit valve door 550 issealed against move. In one embodiment, the slits 578 on the surfacefacing the inside of the chamber are covered with a bellows 558, 560which is held in place by a clamp 556, 562. Similar to the bellowsdiscussed above, the bellows 558, 560 prevent particles that may begenerated from movement of the slit valve door 550 from entering theprocessing area and contaminating the substrate.

The top surface 580 of the slit valve body may also have a bellows 564covered by a clamp 566 to hold bearing plates 568 within the slot 582between moving surfaces. The bearing plates 568 may have a thicknessthat changes from the edge to the center of the bearing plate 568 tomake an arc shape. When the slit valve door 550 is sealed to thechamber, the second body 586 moves relative to the first body 584 andmoves along the bearing plate 568. The second body 586 is coupled to thefirst body 584 at the edge thereof. The first body 584 has a cover 570for covering a centering ring with porous media 572 that permits air orgas to enter or leave the path 574 where the particles may be generated.The particles will be trapped inside the cavity and the pressure insidecavity can be kept the same as the pressure side of door. This is oneexample of a breathable filter plug discussed above.

FIG. 6A is an isometric view of a slit valve door 600 according to oneembodiment. FIG. 6B is a blown up view of the slit valve door 600 ofFIG. 6A. The slit valve door 600 comprises a first body 602, seal caps606 for coupling a bellows 604 between the second body 608 and the firstbody 602, an O-ring 610 for sealing the slit valve door 600 to thechamber, seal caps 612 for coupling a bellows between the first body 602and the second body 608, and slide pads 616 for permitting the secondbody 608 to move relative to the first body 602 when the chamber isevacuated. In one embodiment, the slide pads 616 may comprise poly etherether ketone. In another embodiment, the slide pads 616 may comprisepolytetrafluoro ethylene. One or more slide pads may be spaced betweenthe first body 602 and the second body 608.

FIG. 7 is a plan view of an illustrative processing system 700, such asa linear or cluster tool, having one embodiment of a vacuum transferchamber 706, one or more load lock chambers 704 and a plurality ofprocessing chambers 708. A factory interface 702 coupled by the loadlock chamber 704 to the transfer chamber 706 and includes a plurality ofsubstrate storage cassettes 714 and an atmospheric robot 712. Theatmospheric robot 712 facilitates transfer of substrates 716 between thecassettes 714 and the load lock chamber 704.

The substrate processing chambers 708 are coupled to the transferchamber 706. The substrate processing chambers 708 may be configured toperform at least one of a chemical vapor deposition process, a physicalvapor deposition process, an etch process or other large area substratemanufacturing process suitable for fabricating a flat panel display,solar cell or other device. Generally, large area substrates have a planarea of at least 1 square meter, and may be comprised of a glass orpolymer sheet.

The load lock chamber 704 generally includes at least oneenvironmentally-isolatable cavity having one or more substrate storageslots defined therein. In some embodiments, a plurality ofenvironmentally-isolatable cavities may be provided, each having one ormore substrate storage slots defined therein. The load lock chamber 704is operated to transfer substrates 716 between an ambient or atmosphericenvironment of the factory interface 702 and the vacuum environmentmaintained in the transfer chamber 706.

A vacuum robot 710 is disposed in the transfer chamber 706 to facilitatetransfer of a substrate 716 between the load lock chamber 704 and theprocessing chambers 708. The vacuum robot 710 may be any robot suitablefor transferring substrates under vacuum conditions. In the embodimentdepicted in FIG. 7, the vacuum robot 710 is a polar or frog-leg robotthat generally includes a robot base 760 which houses one or more motors(not shown) utilized to control the position of an end effector 762. Theend effector 762 is coupled to the base 760 by a linkage 764. The loadlock chamber doors discussed herein may be used to seal the load lockchamber 704 from the transfer chamber 710 and also from the factoryinterface 702.

It is to be understood that while the invention has been shown withvertically oriented slit valve doors, the invention is equallyapplicable to horizontally oriented doors that are substantiallyparallel to the ground when in their sealing position.

By permitting a portion of the slit valve door to move with the chamberas the chamber is evacuated and/or vented, the amount of particlesgenerated between the slit valve door and the chamber may be reduced andthus, substrate contamination may be reduced.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A slit valve door, comprising: a first body; a second body that isseparate from the first body and that is movable relative to the firstbody, the second body having a first surface and a second surfacesubstantially perpendicular to the first surface; a bearing coupledbetween the first body and the second body; a first bellows coupled tothe first body and the first surface of the second body; and a secondbellows coupled to the first body and the second surface of the secondbody.
 2. The slit valve door of claim 1, wherein the bearing comprises amaterial selected from the group consisting of poly ether ether ketoneand poly tetrafluoro ethylene.
 3. The slit valve door of claim 2,further comprising an O-ring coupled to the first body and the secondbody.
 4. The slit valve door of claim 1, further comprising an O-ringcoupled to the first body and the second body.
 5. A slit valve door,comprising: a first body; a second body coupled to the first body at anedge thereof and spaced from the first body such that a slit is presentbetween the first body and the second body, the second body having afirst surface and a second surface substantially perpendicular to thefirst surface; a first bellows coupled to the first body and the firstsurface of the second body and over the slit; and a second bellowscoupled to the first body and the second surface of the second body. 6.The slit valve door of claim 5, further comprising an O-ring coupled tothe first body and the second body.
 7. A load lock chamber, comprising:a load lock chamber body having at least one opening formed through afirst surface thereof; a slit valve door, the slit valve doorcomprising: a door body having a first body and a second body spacedfrom the first body, the second body having a first surface and a secondsurface substantially perpendicular to the first surface; a firstbellows flexibly coupled to the first body and the first surface of thesecond body; a second bellows coupled to the first body and the secondsurface of the second body; and a slit valve door actuator coupled withthe slit valve door and the chamber body.
 8. The chamber of claim 7,wherein the slit valve door is rotatable about an axis to pivot the slitvalve door relative to the load lock chamber body from a first positioncontacting the load lock chamber body and a second position spaced fromthe load lock chamber body.
 9. The chamber of claim 7, furthercomprising an O-ring coupled to the slit valve door.
 10. The chamber ofclaim 7, wherein an air pocket is enclosed between the first body andthe second body.
 11. The chamber of claim 7, further comprising one ormore bearings disposed between the first body and the second body. 12.The chamber of claim 11, wherein the one or more bearings comprise amaterial selected from the group consisting of poly ether ether ketoneand poly tetrafluoro ethylene.
 13. The chamber of claim 12, furthercomprising a clamp coupled to at least one of the first bellows and thefirst body.
 14. The chamber of claim 7, further comprising a clampcoupled to at least one of the first bellows and the first body.